This is @simonw’s Lethal Trifecta [1] again - access to private data and untrusted input are arguably the purpose of enterprise agents, so any external communication is unsafe. Markdown images are just the ones people usually forget about
[1] https://simonwillison.net/2025/Jun/16/the-lethal-trifecta/
Good point around the markdown image as an untrusted vector. Lethal trifecta is determnistically preventable, it really should be addressed wider in the indutry